#ObjectScript

Hi Developers!

Many of you publish your InterSystems ObjectScript libraries on Open Exchange and Github.

But what do you do to ease the usage and collaboration to your project for developers?

In this article, I want to introduce the way how to introduce an easy way to launch and contribute to any ObjectScript project just by copying a standard set of files to your repository.

Let's go!

Hi, colleagues!

When you export the Caché ObjectScript code to VCS (Git, SVN, Perforce, etc) do you export the Storage schema for persistent classes? If so, what are the Pro/Contra?

Thanks!

Hi, Community!

Last weekend we held the Final of InterSystems Contest on Caché, DeepSee and iKnow under the aegis of IT Planet Student Championship in Ekaterinburg. BTW, this year we had more than 1,400 participants in InterSystems Contest.

Hello,
I'm currently working on a custom version control implementation.
I'd like to show differences between a copy of a previously saved routine as a merge of the ^ROUTINE Global and the current version of that same routine.

I've found legacy Documentation for %RCMP which does the trick in the terminal but I'd like a similar result stored inside a variable.
I also want to show differences, not only see if they are the same or not.

The management portal has that exact feature, so maybe someone can direct me to the function that is being used there.

Hi developers!

Want to discuss with you the case of %Status.

If you familiar with ObjectScript you know what is it. I'd love to hear the history of the case why it had appeared in ObjectScript but it turned out that almost every system/library classmethods return %Status and there is a whole set of tools to deal with it.

What is does it gives you the responsibility to check the value or %Status of every system method you call.

E.g. if you save the data of the persistent class, you should never call like this:

do obj.%Save()

you need to call:

set sc=obj.%Save()

if $$$ISERR(sc) do // something or quit.

Ladies and gentlemen, good news for our town.

It finally happened - M was put in the cell.

Caché offers a number of methods for going through a collection and doing something with its elements. The easiest method uses a while-loop and lets you fulfill the task in an imperative manner. The developer needs to take care of the iterator, jumping to the next element and checking if the loop is within the collection.

Hi guys!

As you know there are two (at least) ways to get the stored value of the property of InterSystems IRIS class if you know the ID of an instance (or a record).

1. Get it by as a property of an instance with "Object access":

ClassMethod GetPropertyForID(stId As %Integer) As %String

{

set obj=..%OpenId(stId)

return obj.StringData

}

2. Get it as a value of a column of the record with "SQL access":

Class Queries in InterSystems IRIS (and Cache, Ensemble, HealthShare) is a useful tool that separates SQL queries from Object Script code. Basically, it works like this: suppose that you want to use the same SQL query with different arguments in several different places.In this case you can avoid code duplication by declaring the query body as a class query and then calling this query by name. This approach is also convenient for custom queries, in which the task of obtaining the next row is defined by a developer. Sounds interesting? Then read on!

Hi Developers!

Sometimes we need to import CSV data programmatically to InterSystems IRIS either from CSV or from URL. And we expect the class with proper datatypes to be created and the data to be imported.

I published a module csvgen on Open Exchange which does exactly that.

If you just need the CSV file be imported into IRIS you can do the following:

USER>do ##class(community.csvgen).Generate("/usr/data/titanic.csv",,"Data.Titanic")

Class name: Data.Titanic
Header: PassengerId INTEGER,Survived INTEGER,Pclass INTEGER,Name VARCHAR(250),Sex VARCHAR(250),Age INTEGER,SibSp INTEGER,Parch INTEGER,Ticket VARCHAR(250),Fare MONEY,Cabin VARCHAR(250),Embarked VARCHAR(250)
Records imported: 891
USER>

Or if you have the CSV on the internet, e.g. COVID-19 Data on Github you can get the data in the following way:

USER>d ##class(community.csvgen).GenerateFromURL("https://raw.githubusercontent.com/CSSEGISandData/COVID-19/master/csse_covid_19_data/csse_covid_19_daily_reports/05-29-2020.csv",",","Data.Covid19")

Class name: Data.Covid19
Header: FIPS INTEGER,Admin2 VARCHAR(250),Province_State VARCHAR(250),Country_Region VARCHAR(250),Last_Update DATE,Lat MONEY,Long_ DOUBLE,Confirmed INTEGER,Deaths INTEGER,Recovered INTEGER,Active INTEGER,Combined_Key VARCHAR(250),Incidence_Rate DOUBLE,Case-Fatality_Ratio DOUBLE
Records imported: 3522
USER>

Hi, folks!

There is an interesting discussion in the neighboring topic which raises a question for me: is there any reason to have %Status as a return value for COS method?

Hi!

I believe the simplest is (to work with csv delimited by ";"):

set file = ##class(%File).%New( "data.csv" )
    set sc = file.Open( "R" ) 
    if $$$ISERR(sc) quit    ; or do smth

    while 'file.AtEnd {
        set str=file.ReadLine() 
        for i=1:1:$length( str, ";" ) {
            set id=$piece( str, ";" ,i ) 
            write !, id  // or do smth
        }
    }
    do file.Close()

Possible options:

different variants of error handling with sc code.

Embrace while loop into try/catch block.

And what's yours?

I'm pleased to announce the latest version of the renewed for ObjectScript, which is now available with a lot of new features.

This new extension is a fork of previously developed extension in different repository originally started by @Oleg Dmitrovich.